Showman’s Locomotives

Throughout the last thirty years of the 19th century fairground rides continued to develop from small, simple hand turned rides which would appear on village greens and the like into large complex riding machines, requiring major sources of power to run them. A parallel development of mechanical organs by firms such as Marenghi and Gavioli provided the opportunity for loud music, reliably produced. Again, such organs required a substantive power source.

During this time steam engines were becoming an increasingly common sight on British farmland and showfolk were quick to understand the usefulness of steam as a motive power, not only for transport, but also powering this new generation of rides. Therefore, agricultural engines and steam tractors became useful for pulling fairground loads.

Double cranks, bellies and compounds

Engine builders meanwhile began developing steam powered road locomotives. Although of various sizes they shared a high level of specification including three gears (as opposed to the one or two gears of agricultural engines), fully sprung axles, and extra water tanks (known as ‘belly tanks’) mounted under the boiler barrel.

These developments increased the speed of the engines from the usual 7-8 mph to between 10 and 15mph. They also increased the range in terms of needing water (steam locomotives needed industrial quantities of the stuff), which increased from 10 to 15 miles to 25 to 30 miles.

Road locomotives followed a twin cylinder lay out known as a double crank. High-pressure steam (around 200psi) was fed into a small cylinder and then exhausted into a second, larger cylinder to create more efficient use of steam.

Standard steam practice is to drive the piston in both directions, rather than relying on inertia to return the cylinder (as with an internal combustion engine). This system is known as “compounding” and thus engines were known as “single crank compounds” or “double crank compounds”. The initials “SCC” or “DCC” can often be seen cast into maker’s plates and specification plates.

It didn’t take a genius to understand that with a little modification these road locomotives could be an ideal for fairground work. An extension forward from the smoke box (known as a perch bracket) could be used to mount a dynamo, which could be driven from the engine’s flywheel, and the cab extended full length to provide weather protection to the electrics. This was the basis of what became the Showman’s Engine, which in true showland tradition soon became festooned with twisted brasswork and glorious coach painting.

The major manufacturers of Showman’s Engines were Burrells of Thetford and Fowlers of Leeds, although firms like Maclaren, Foden, Foster and others also included such machines in their catalogues.

As fairground rides got bigger so did the locomotives, culminating in the development of what is collectively known as the Scenic. Basically the same as the standard type of Showman’s Engine, it had two important modifications. Firstly a large ‘A’ frame was built into the tender at the back of the engine. A jib could be attached to the engines towing bracket and the wire rope run out from the engines winding drum. Large pins were removed from the engine’s driving wheels to disconnect the drive and the result was a mobile crane, which could be used to help assemble the rides and in particular lift the heavy ‘cars’ onto the tracks.

Second, an extra bracket was bolted onto the boiler between the steam chest and the chimney. This carried a type of dynamo known as an ‘exciter’. Driven from the end of the dynamo armature, it ‘excites’ the field coils in the dynamo, allowing a much greater output. Whereas a standard dynamo would put out something in the region of 120 to 150 amps the Scenic engines were capable of putting out the 300 plus amps that large rides demanded (at 110 volts DC). The Scenic turned out to be the end of the road for Showman’s Engines. Technology was moving on and it wasn’t long before steam power conceded defeat to diesel and petrol powered vehicles, along with more sophisticated mobile power plants.

This feature was originally written by Matt Swindlehurst and appeared, with permission, on the now defunct in 2002.